1. Technical Field
This application generally relates to computer data storage, and more particularly to performing data operations in connection with computer data storage.
2. Description of Related Art
Computer systems may include different resources used by one or more host processors. Resources and host processors in a computer system may be interconnected by one or more communication connections. These resources may include, for example, data storage devices such as disk drives. These data storage systems may be coupled to one or more host processors and provide storage services to each host processor. An example data storage system may include one or more data storage devices that are connected together and may be used to provide common data storage for one or more host processors in a computer system.
A host processor may perform a variety of data processing tasks and operations using the data storage system. For example, a host processor may perform basic system I/O operations in connection with data requests, such as data read and write operations and also administrative tasks, such as data backup and mirroring operations.
Host processor systems may store and retrieve data using a storage device containing a plurality of host interface units, disk drives, and disk interface units. The host systems access the storage device through a plurality of channels provided therewith. Host systems provide data and access control information through the channels to the storage device and storage device provides data to the host systems also through the channels. The host systems do not address the disk drives of the storage device directly, but rather, access what appears to the host systems as a plurality of logical disk units or logical volumes. The logical disk units may or may not correspond to the actual disk drives. Allowing multiple host systems to access the single storage device unit allows the host systems to share data stored therein.
Data operations issued from a host may utilize switching fabric comprising a combination of hardware and/or software in routing a data operation and associated communications between a host and a target data storage device. The switching fabric may include hardware, such as switching hardware, and software. Software used in routing operations between a host and a data storage device may utilize a layered approach. Calls may be made between multiple software layers in the switching fabric in connection with routing a request to a particular device. One drawback with the layering approach is the overhead in performing the calls that may result in increasing the amount of time to dispatch the data operation to the data storage device.
Thus, it may be desirous and advantageous to utilize a technique that efficiently dispatches a data operation to a data storage device. In particular, it may be advantageous to utilize this technique in connection with more commonly performed data operations.